8S On definite Proportions. 



direct experiments with burning sulphur, is a task- of in- 

 superable ditTicuhv. I therefore chose rather to convert a 

 sulj-hiie into a sulphate bv means of t'ne nitric acid. 



Neutral muriate ot barvta was mixed with a sohuion of 

 crystallized sulphite of aniinonia, the precij)itate v\as placed 

 on a fiUcr, and washed wiih boiling v\ater till the water had 

 no effect on a solution of Mlver; the niass was then dried 

 by pressure between the folds of some thick blotting paper, 

 quickly s|)read in a saucer, and dried in a ^^ arm stove. 

 When I dissolved a little of this salt in muriatic acid, the 

 fluid was not perceptiblv turbid, so that scarcely any sul- 

 phate of baryta was contained in it. 



1.) Three grammes of this sulphite of baryta were put 

 into a flask; nitric acid was poured on them, and thev were 

 digested with it as long as any nitrous gas was evolved, and 

 then dried and ignited in the flask. The mass weighed 

 only 3"17 gr., it showed not the sliehtest trace of an excess 

 of baryta. But 3-1 7 gr. of the suljihate of baryta contain 

 •66 X 3- !7 = 2-0922 of the earth. 



2.) Three grammes of the same salt were mixed with 

 30 of ignited yellow oxide of lead, and the whole was 

 heated in a small glass retort, furnished with a long and 

 well crrked neck. The necTc, in which the water of cry- 

 stallization of the salt was collected, was cut oflT and 

 weighed. By the evaporation of the water it lost '0425 in 

 weight. The water was entirely without taste. 



The sulphite of baryta consisted therefore of 



Baryta £09'22 6974 



Sui])hurous acid 8653 2S-84 



Water 4-25 1-42 



3.) I again dissolved three grammes of the same salt in 

 nitric acid, and when the effervescence was ended, added 

 some nitrate of baryta, as a test of sulphuric acid, to the 

 filtered solution; it did not become turbid, any more than 

 another portion into which sulphuric acid was dropped; 

 consequently the baryta is united with the same quantity 

 of sulphur in the sulphite as in the sulphate, that is, with 

 20"9 for every 100 parts of the earth; and we shall see 

 hereafter, that if there actually exists a combination be- 

 tween the base of baryta and sulphur, the proportion of 

 this base, and of sulphur in it, must be the same as in the 

 sulphate and the sulphite; and also, at least as I presume, 

 in the sulpliuret, and in the hvdrosulphuret, or hvdrotheate 

 of barvta, although the experiments which I have made 

 with these last combinations have not afforded me v^ry sa- 

 tisiactory results. 



Now, 



